Significant Accounting Policies (Narrative) (Details)		12 Months Ended
	May 09, 2019	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Apr. 30, 2020 USD ($)	Dec. 31, 2018 USD ($)
Impairment of long-lived assets		$ 0
Impairment of in-process research and development		0
Unrecognized tax benefits		$ 0	$ 0
Conversion ratio of reverse stock split	0.0714	0.0714
Common stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01
Common stock, shares authorized | shares		217,000,000	217,000,000
Derivative liability, fair value		$ 0			$ 1,100,000
Lease liability		12,428,000		$ 11,700,000
Right-of-use asset		10,790,000	$ 2,028,000	$ 11,000,000
Accumulated deficit		(179,702,000)	(157,521,000)
Goodwill, Impairment Loss		$ 0
Estimated incremental borrowing rate (as a percent)				12.90%
Measurement Input, Discount Rate [Member]
IPR&D measurement input		16.7
Australian Taxation Office [Member]
Tax rebates received		$ 700,000	$ 1,300,000